The present invention relates generally to transmission systems for angle-modulated wave signals and to cross-talk component cancellation circuits therein. More particularly, the invention relates to a circuit for effectively canceling the cross-talk component of the angle-modulated wave signal of an adjacent channel admixed into the angle-modulated wave signal of one channel among the angle-modulated wave signals of a plurality of channels picked up from a multichannel record disc.
In a discrete 4-channel record disc, for example, the direct-wave sum signal and the angle-modulated wave difference signal of the signals of two channels out of the four channels are multiplexed and used as a right-channel signal. The direct-wave sum signal and the angle-modulated wave difference signal of the other two channels are multiplexed and used as a left-channel signal. The right-channel and left-channel signals thus obtained are recorded on the right and left walls of the same sound groove in the record disc.
In the recording system and the reproducing system for a multichannel record disc of this kind, cross-talk easily occurs between the angle-modulated wave signals of the right and left channel signals of the two walls of the sound groove. When this cross-talk occurs, the angles of the angle-modulated wave signals vary and give rise to intermodulation distortion thereby developing distortions in the demodulated signals.
One method known heretofore for reducing this cross-talk component comprises controlling the levels of the signals resulting from the demodulation of the angle-modulated wave signals responsively in accordance with the envelope of the angle-modulated wave signals. By this method, however, since reduction of the cross-talk component is carried out with respect to the demodulated signal, the cross-talk component cannot be completely removed.